Electrostatic machine.



I. GHILARDUGGI. ELECTROSTATIC MACHINE. APPLICATION I'IILBD JULY 2,1908.

1,011,939. Patented Dec.19,1911.

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COLUMBIA PLANdGRAH-l CO-.WA5HINGTON. l), c

UNITED STATES PATENT OFFICE.

FRANCESCO GHILARDUCCI, 0F ROME, ITALY.

ELECTROSTATIC MACHINE.

Application filed July 2, 1908.

T 0 all whom 'it may concern:

Be it known that I, FRANCESCO GHILAR- DUocI, a subject of the King ofItaly, residing at Rome, Italy, professor at the Roman University, haveinvented certain new and useful Improvements in Electrostatic Machines,of which the following is a specification.

My invention relates to electrostatic machines, as they are used forproducing Rontgen rays, for space telegraphy and inelectro-therapeutics, and has for its objectto make certain improvementsin electrostatic machines of a well-known type, such as the I-Ioltzmachine.

My invention more particularly consists in making the stationary disk intwo parts, supported by the insulating casing, and provided with flangesat their opposite straight edges, and mounting the rotatable disk on ashaft, supported independently of the easing upon a wall or other rigidstructure. The most important advantage obtained by this improvement isthe prompt and certain self-excitability of the machine under anyatmospheric conditions, and in addition an enormously superior output isobtained from my machine as compared with other machines of equaldimensions, because the rotatable disk can be operated at anextraordinarily high speed, whereas the support for the stationary diskcan be made of glass, which is a good insulating material. On account ofthe gap between the two parts of the stationary disk and on account ofthe flanges provided at their opposed straight edges, a most perfectinsulation of the two parts of the stationary disk is effected. Mymachine, moreover, works perfectly even in a humid atmosphere and istherefore always ready to perform any radio-telegraphic andelectrotherapeutic operations.

In the accompanying drawing, Figure l is a front view of anelectrostatic machine of the well-known Holtz type with my newimprovements; Fig. 2 is a side View of the machine as shown in Fig. 1;Fig. 3 a perspective view of a section of the stationary disk.

1 designates the rotatable disk, which is made of hard rubber, or glass,or the like, and is mounted on a shaft 4, which shaft has no support atits front end, but is journaled in a bearing provided in a socket of awall or other rigid body, so that a very Specification of LettersPatent.

Patented Dec. 19, 1911.

Serial No. 441,697.

rapid rotation of about 3,000 revolutions per minute may be given to thedisk without setting up oscillation therein. By thus journaling theshaft 4, carrying the rotatable disk 1 in a bearing independent of thecasing, the bottom plate of the latter may be made of glass, since it isnot subjected to any strains, which would occur, if the shaft at werejournaled in the casing. This arrangement results, at the same time, ina great gain in insulation. The casing is therefore made entirely ofglass, and the sections 2 and 3 of the stationary disk are supportedeach from the top 5 and the bottom plate 6 of the casing, so as to leavea gap of at least one centimeter between their straight edges, asclearly shown in Fig. 1. In the center of their straight edges, thesections 2 and 3 are recessed, so as to form a circular opening, throughwhich the shaft 4 supporting the disk 1 passes. The sections 2 and 3 ofthe stationary disk are also made of hard rubber, or preferably ofglass, and are each provided at their straight edges with an uprightflange 7 at right angles to the planes of the sections and preferablyabout eight centimeters high. The distance between the two flanges isabout 1 centimeter. Each section is provided with a tinfoil armature 8,which is covered with paraffin paper 9. The armatures 8 are connectedwith the brush-carriers 10 and 11, which 'are adapted to slide on thefront face of the disk 1, while the latter rotates. By a metal rod 14there is connected to each brush-carrier a small capacity 12 and 13respectively. By the arrangement of these capacities, the inductiveeffect of the machine is increased and a corresponding potentialincrease is effected. The capacities are preferably so located thattheir rims are about three centimeters away from the collecting combs15; The collecting combs 15 are supported from the top 5 of the casingand terminate in small knobs 26, which are adjustable by means ofbrass-rods provided with ebonite handles, so that the knobs 26 can bemoved nearer to and farther away from other knobs 27, whereby a variablespark gap may be formed. The two sections of the stationary disk can bebrought into contact with the ground by means of two metal rods 22,adapted to slide in insulating tubes 23, secured to the under side ofthe bottom plate 6 of the casing. Contact is made between the said metalrods and the armature by the pulling of a cord 25, whereby the armaturesof the two sections of the stationary disk are discharged, and thepolarity of the machine is reversed. Thus the polarity of the machinemay be changed even at a distance. The grounding of the discharges iseffected by means of metal chains 2%, which, as shown in Fig. l, areconnected to the metal rods 22.

As seen from Figs. 1 and 2, a neutralizing rod is provided, provided ateach of its metallic terminals 16 with three brushes. The said terminalsare connected by a bent wire 17, which is bow-shaped and fixed at itscenter to a metal rod 18, adapted to slide in an insulating tube 19,secured to the front plate of the casing. By means of a handle 21attached to the rod 18, the latter can be turned to give a right or lefthand inclination to the neutralizing red, the effect of this being tovary the tension, or to reverse the polarity of the machine. Thepolarity is reversed by giving the neutralizing rod a maximum right handinclination and then returning it to its normal position, shown inFig. 1. By moving the neutralizing rod nearer to the disk 1, or fartheraway therefrom, also the electric tension of the machine can be varied.7

By making the stationary disk of two sections, as described and shown,and providing a neutralizing rod, the machine can be easily and promptlydeenergized by giving the neutralizing rod a turn to move it from itsnormal position shown in Fig. 1 into a position in which it will lieabove the gap formed between the straight edges of the two sections 2and 3, The deenergizing of the machine can also be obtained by establishing a metallic connection between the two armatures S of thesections Qand 3 of the stationary disk. As soon as the neutralizing rodis returned to its normal position, or after the metallic connectionbetween the armatures has been interrupted, the machine immediatelybecomes again energized.

In conjunction with the knobs 26 above referred to, two condensers 28 ofadjustable capacity may be provided to increasethe strength of theelectric discharges.

I claim:

1. In an electrostatic machine of the IIoltz or a similar type, thecombination with an insulating casing of a rotatable ebonite disksupported independently of the said casing, a stationary disk made ofinsulating material, and comprising two independent sections, forming agap between them and supported each by the top and bottom of saidcasing, an armature on each of said sections and brushes connected tosaid armature and adapted to slide on the front faces of said rotatabledisk.

2. In an electrostatic machine the combination with an insulatingcasing, a rotatable shaft journaled independently of said casing, anebonite disk mounted on said shaft, a stationary disk made of insulatingmaterial, and comprising two sections, forming a gap between them andsupported each by the top and bottom of the said casing, an armatureprovided on each section, brushes connected to said armatures andadapted to slide on the front face of said disk during its rotation,collecting conductors, a neutralizing rod, a plurality of brushescarried at its terminals, an insulating tube carried by the front plateof the casing, a rod carrying said neutralizing rod and capable ofadjustment in said insulating tube, an operating handle for moving saidmetal rod in said tube both loi'igitudinally and axially.

3. In an electrostatic machine the combination with an insulatingeasing, a rotatable shaft journaled independently of said casing, anebonite disk mounted 011 said shaft, a stationary disk made ofinsulating material, and comprising two sections, forming a gap betweenthem and supported each by to the top and bottom of the said casing, anarmature provided on each section, brushes connected to said armaturesand adapted to slide on the front face of said disk during its rotation,collecting conductors, a neutral izing rod, a plurality of brushescarried at its terminals, an insulatil'lg tube carried by the frontplate of the casing, a rod carrying said neutralizing rod and capable ofadjustment in said insulating tube, an operating handle for moving saidmetal rod in said tube both longitudinally and axially, and insulatingtubes attached to the bottom of the casing, and metal rods adapted toslide in said insulating tubes and to connect. the armatures of the twosections of the said stationary disk.

In testimony whereof I have a'liixed my signature in presence of twowitnesses.

FRANCESCO GHILARDUCCI.

Witnesses G. B. ZANARDO, ZLAMIIJLLE Pnnsox.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. (1.

